Generally, a ventilating system is a system for discharging polluted indoor air to the outdoor and sucking fresh outdoor air to the indoor, and the system includes an air cleaner for removing dust and foreign materials contained in the outdoor air, and a heat exchanger for transferring heat of the discharged indoor air to the sucked outdoor air.
FIG. 1 is a perspective view showing a conventional ventilating system.
The ventilating system includes a case 2 which is mounted on a wall for dividing indoor and outdoor, blowing fans 4 and 6 which are mounted in the case 2, for ventilating air which is sucked and discharged, an air cleaner (not shown) which is installed in a portion to which the outdoor air inside the case 2 is sucked, for cleaning the outdoor air sucked to the indoor, and a heat exchanger 8 which is positioned inside the case 2, for performing a heat exchanging operation of indoor air discharged the outdoor and outdoor air sucked to the indoor.
Here, the case 2 is disposed in a hole formed on the wall for diving the indoor and outdoor, and accordingly, one side is positioned indoors and the other side is positioned outdoors. At this time, an outdoor suction hole 10 to which outdoor air is sucked and an indoor discharging hole 12 through which indoor air is discharged to the outdoor are respectively formed on the side wall of the case 2 positioned outdoors, and an indoor discharging hole 14 through which outdoor air is discharged to the indoor and an indoor suction hole 16 through which indoor air is sucked are respectively formed on the side wall of the case 2 positioned indoors.
The blowing fans 4 and 6 includes a discharging blowing fan 4 which is installed in a position connected with the outdoor discharging hole 12, for providing a blowing pressure for discharging the indoor air to the outdoor, and a suction blowing fan 6 which is installed in a position connected with the indoor discharging hole 14, for providing a blowing pressure for sucking the outdoor air to the indoor.
FIG. 2 is a perspective view showing a conventional heat exchanger of a ventilating system, and FIG. 3 is a partial perspective view showing the conventional heat exchanger of a ventilating system.
The conventional heat exchanger 8 includes a plurality of base plates 20 which are laminated at a regular interval in a shape of a thin plate, first corrugation plates 22 which are respectively laminated in the spaces among the base plates 20, through which indoor air passes, and second corrugation plates 24 which are respectively laminated in the base plates 20 to be mutually crossed with the first corrugation plates 22 in turn, through which outdoor air passes.
Here, the first and second corrugation plates 22 and 24 are curved in a triangular shape, and indoor and outdoor air passes to the inner and outer sides thereof, thus to mutually exchange heat.
Such heat exchanger 8 is formed in a rectangular shape by sequentially laminating the first corrugation plates 22, base plates 20, and second corrugation plates 24. The upper and lower surfaces of the heat exchanger 8 are respectively closed by the base plate 20, and the both side surfaces of the heat exchanger are connected with the outdoor suction hole 10 and indoor discharging hole 14, and outdoor air passes therethrough. Another both side surfaces of the heat exchanger are respectively connected with the outdoor discharging hole 12 and indoor suction hole 16, and indoor air passes therethrough.
That is, as the outdoor air which passes the first corrugation plates 22 and indoor air which passes the second corrugation plates 24 pass while being crossed with each other, heat exchange is performed by transferring heat of the indoor air through the base plates 20.
The operation of the conventional heat exchanger for the ventilating system with the above structure will be described as follows.
When the sucking blowing fan 6 is driven, the outdoor air is sucked to the outdoor suction port 10 and is supplied to the indoor through the indoor discharging hole 14 by passing the first corrugation plate 22. When the discharging blowing fan 4 is driven, the indoor air is sucked through the indoor suction hole 16 and discharged to the indoor through the outdoor discharging hole 12 by passing the second corrugation plate 24.
Here, as the outdoor air passing in the first corrugation plate 22 and indoor air passing the second corrugation plate 24 flow while being crossed with each other, heat in the indoor air is transferred to the outdoor air through the base plate 20, and the outdoor air which sucked the heat of the indoor air is supplied to the indoor.
As described above, since heat in the discharged indoor air is sucked to the outdoor air and discharged to the indoor, rapid temperature change of the indoor air can be prevented in case of operating ventilation.
However, in the conventional heat exchanger of the ventilating system, the first and second corrugation plates 22 and 24 are formed in a shape of a plate having a corrugation of a predetermined shape, and a boundary layer S is developed as the air flowing in the first and second corrugation plates moves along from the inlet side to the outlet side. Therefore, heat transfer efficiency is degraded and indoor temperature is rapidly changed in case of ventilating since the outdoor air sucked to the indoor could not absorb heat in the indoor air. Also, energy consumption for recovering the indoor air is increased and indoor air conditioning performance is degraded.
That is, as shown in FIG. 4, particles of viscous air which flow inside a pipe of the first and second corrugation plates 22 and 24 stick on the surface contacted on a surface of the inside of the pipe when the viscous air flows on the surface of the inside of the pipe. As the air gets apart from the surface of the inside of the pipe, the air recovers the speed and gains a speed of a free flow in a position at a predetermined distance from the surface of the solid material. At this time, as the air is get apart from the surface of the inside of the pipe, a boundary layer S is formed.
As described above, as the air flowing on the surface of the inside of the pipe is processed, the boundary layer is developed and the air gets apart from the surface of the inside of the pipe, thus to degrade heat transfer efficiency that the heat of the indoor air is transferred to the outdoor air through the base plate 20.